PDF(Pubmed)
Abstract：
BACKGROUND: Research has shown that visual perceptual learning (VPL) is related to modifying neural activity in higher level decision-making regions. However, the causal roles of the prefrontal and visual cortexes in VPL are still unclear. Here, we investigated how anodal transcranial direct current stimulation (tDCS) of the prefrontal and visual cortices modulates VPL in the early and later phases and the role of multiple brain regions.
METHODS: Perceptual learning on the coherent motion direction identification task included early and later stages. After early training, participants needed to continuously train to reach a plateau; once the plateau was reached, participants entered a later stage. Sixty participants were randomly divided into five groups. Regardless of the training at the early and later stages, four groups received multitarget tDCS over the right dorsolateral prefrontal cortex (rDLPFC) and right middle temporal area (rMT), single-target tDCS over the rDLPFC, and single-target tDCS over the rMT or sham stimulation, and one group was stimulated at the ipsilateral brain region (i.e., left MT).
RESULTS: Compared with sham stimulation, multitarget and two single-target tDCS over the rDLPFC or rMT improved posttest performance and accelerated learning during the early period. However, multitarget tDCS and two single-target tDCS led to equivalent benefits for VPL. Additionally, these beneficial effects were absent when anodal tDCS was applied to the ipsilateral brain region. For the later period, the above facilitating effects on VPL induced by multitarget or single-target tDCS disappeared.
CONCLUSIONS: This study suggested the causal role of the prefrontal and visual cortices in visual motion perceptual learning by anodal tDCS but failed to find greater beneficial effects by simultaneously stimulating the prefrontal and visual cortices. Future research should investigate the functional associations between multiple brain regions to further promote VPL.
METHODS: Perceptual learning on the coherent motion direction identification task included early and later stages. After early training, participants needed to continuously train to reach a plateau; once the plateau was reached, participants entered a later stage. Sixty participants were randomly divided into five groups. Regardless of the training at the early and later stages, four groups received multitarget tDCS over the right dorsolateral prefrontal cortex (rDLPFC) and right middle temporal area (rMT), single-target tDCS over the rDLPFC, and single-target tDCS over the rMT or sham stimulation, and one group was stimulated at the ipsilateral brain region (i.e., left MT).
RESULTS: Compared with sham stimulation, multitarget and two single-target tDCS over the rDLPFC or rMT improved posttest performance and accelerated learning during the early period. However, multitarget tDCS and two single-target tDCS led to equivalent benefits for VPL. Additionally, these beneficial effects were absent when anodal tDCS was applied to the ipsilateral brain region. For the later period, the above facilitating effects on VPL induced by multitarget or single-target tDCS disappeared.
CONCLUSIONS: This study suggested the causal role of the prefrontal and visual cortices in visual motion perceptual learning by anodal tDCS but failed to find greater beneficial effects by simultaneously stimulating the prefrontal and visual cortices. Future research should investigate the functional associations between multiple brain regions to further promote VPL.
摘要：
背景：研究表明，视觉感知学习（VPL）与修改更高级别的决策区域中的神经活动有关。然而,前额叶和视觉皮层在VPL中的因果作用尚不清楚.这里,我们研究了前额叶和视觉皮层的阳极经颅直流电刺激(tDCS)如何在早期和后期调节VPL,以及多个脑区的作用.
方法：关于连贯运动方向识别任务的感知学习包括早期和后期。经过早期训练,参与者需要不断训练才能到达高原；一旦到达高原，参与者进入了后期阶段。60名参与者被随机分为五组。不管前期和后期的训练,四组在右背外侧前额叶皮层（rDLPFC）和右颞中区（rMT）接受多目标tDCS，rDLPFC上的单目标tDCS，和rMT或假刺激的单目标tDCS，一组在同侧大脑区域受到刺激(即，左MT）。
结果：与假刺激相比，rDLPFC或rMT上的多目标和两个单目标tDCS提高了后测性能，并在早期加速了学习。然而,多目标tDCS和两个单目标tDCS为VPL带来了等效的好处。此外,当阳极tDCS应用于同侧大脑区域时,这些有益效果不存在.在后期,上述对多靶标或单靶标tDCS诱导的VPL的促进作用消失。
结论：这项研究表明前额叶和视觉皮层在通过阳极tDCS进行视觉运动知觉学习中的因果作用，但未能通过同时刺激前额叶和视觉皮层来发现更大的有益效果。未来的研究应该研究多个大脑区域之间的功能关联，以进一步促进VPL。
方法：关于连贯运动方向识别任务的感知学习包括早期和后期。经过早期训练,参与者需要不断训练才能到达高原；一旦到达高原，参与者进入了后期阶段。60名参与者被随机分为五组。不管前期和后期的训练,四组在右背外侧前额叶皮层（rDLPFC）和右颞中区（rMT）接受多目标tDCS，rDLPFC上的单目标tDCS，和rMT或假刺激的单目标tDCS，一组在同侧大脑区域受到刺激(即，左MT）。
结果：与假刺激相比，rDLPFC或rMT上的多目标和两个单目标tDCS提高了后测性能，并在早期加速了学习。然而,多目标tDCS和两个单目标tDCS为VPL带来了等效的好处。此外,当阳极tDCS应用于同侧大脑区域时,这些有益效果不存在.在后期,上述对多靶标或单靶标tDCS诱导的VPL的促进作用消失。
结论：这项研究表明前额叶和视觉皮层在通过阳极tDCS进行视觉运动知觉学习中的因果作用，但未能通过同时刺激前额叶和视觉皮层来发现更大的有益效果。未来的研究应该研究多个大脑区域之间的功能关联，以进一步促进VPL。
